The present invention relates to a machine for mechanically machining boards, in particular printed circuit boards. More specifically, the present invention relates to a drilling or milling machine for simultaneously machining a number of packs of printed circuit boards by means of a corresponding number of machining heads.
Machines of the aforementioned type are known wherein the worktable travels along a longitudinal axis, normally referred to as the Y axis, and the machining head is fitted to a carriage sliding transversely on a fixed crosspiece along the so-called X axis. In view of the low output of which they are capable, however, such machines are unsuitable for mass production applications.
As is known, the electronic circuit industry demands an ever-increasing number of printed circuit boards which feature a large number of holes requiring highly accurate, but at the same time low-cost, machining. Drilling machines have therefore been devised featuring a number of drilling heads for simultaneously machining respective packs of printed circuit boards on a single worktable.
One known drilling machine features a number of machining heads on a crosspiece fixed to the machine bed; and the worktable is moved selectively along the horizontal X and Y axes, so that it is extremely complex and expensive in design.
Another machine for drilling printed circuit boards features a fixed worktable, and the crosspiece supporting the machining heads travels along the longitudinal Y axis. The crosspiece supports two machining heads traveling transversely along the crosspiece, connected transversely to each other, and moved along the Y axis by a common drive device.
This type of machine presents several drawbacks, foremost of which are the impossibility of maintaining a precise constant distance between the two connected machining heads; the impossibility of fitting the crosspiece with more than two machining heads; and, finally, the difficulty posed by longitudinal displacement of the crosspiece.